Fuze



sept. 1o, 1963 F. Cf HUTCHISON ETAL l FuzE Filed sept. 21, 1960 L l W W l mw INVENTORS, Frank E- Huc. :his an.

` Charles ELM/'seks @mwa CPCM. QW#

United States Patent O 3,itl3,172 FUZE Fraai: C. Hatchison, Greenfield, Nil., and Gerard Ratcliife, Boston, and Wiliis E. 'lihbetts and Charles il. lieelrs, Breeding, Mass., assigners to the United States o1 America as represented by the Secretary oi the Army lFiled dept. 2l, 1%0, Ser. No. 57,5% l Claim. (Cl. itlZ-f/S) This invention relates to a fuze, and more particularly to a fuze having a delayed arming mechanism.

The present inven-tion has for a primary object a delay mechanism to permit a high explosive charge to detonate after a shell has penetrated a target, such as an aircraft, for some distance whereby greater damage will be done.

Another object of the invention is a delay mechanism for a fuze that provides a primary firing element actuated by the crushing of a proiectile nose to tire a primer whereby pressure is built up behind a secondary ring pin to cause a second detonator in a cylindrical rotor to be detonated and lire the booster charge, thereby constituting a delay train in a fuze.

It is a 4further object to provide -a fuze which is extremely simple in operation and highly eihcient in its action.

The specific nature of the invention as well as other objects and advantages thereof, will clearly 'appear lfrom a description of a preferred embodiment as `shown in the accompanying drawings, in which:

FIG. 1 is yan axial section taken through a fuze constructed in accordance with the invention;

FIG. 2 is a sectional View taken along lines 2 2 of FIG. l and looking in the direction of the arrows;

FlG. 3 is a sectional View taken along lines 3 3 of FG. 1 and looking in the direction of the arrows, the rotor and ball being shown in elevation and the rotor being broken away to reveal the lock spring; and

FlG. 4- is an elevational view of the rotor as viewed from the front.

Referring to the drawings, 1 denotes a fuze generally and comprises an outer body I2 defining an ogival nose portion 3 and 4an externally threaded rearward portion Il for attachment to a projectile, not shown.

Outer body 2 is centrally bored as at 5 to receive fuze operating elements as to be later described. Bore 5 is internally threaded as at 6r, and counterbored as at 7, 8 and 9 for a purpose to be apparent later.

An inner body generally indicated by lll is adapted to be received in bore 5.

inner body itt is generally cylindrical in shape and includes an axial bore l1 in its rearward portion to receive a booster charge 12.

Inner body iti further denes a cylindrical middle portion i3 adapted to iit bore 5 of outer body 2` and is provided with a reduced portion i4 forwardly of portion 13 and `an externally threaded portion l5 adapted to engage threaded portion 6 of outer body 2.

Inner body lil is axially bored as at 16 and counterbo-red as at 17 and the middle portion 13 is provided with a cylindrical bore i8. Middle portion 13 is further bored radially as at 19 and is provided with ports Zi which communicate between bores i@ and space 21 formed by reduced portion l'14?, of inner body iii. Slots 21 `and 22 are provided for purposes as will be later apparent.

Arming -means for the fuze is provided and consists of a cylindrical rotor indicated generally by 23 which is rotatably mounted in cylindrical bore ld. Rotor 23 is transversely bored as at 24 to receive a. detonator 2S. Bore Z4 is crimped at one end with half-moon crimpsd, best` seen in FIG. 3 to prevent dislodgement of detonator 25 from the rotor 23.

Means for preventing rotor 23 from rotating to an lilaiented Sept. 10, 1963 armed position is provided and comprises a bore 27 in rotor Z3 having its axis at 90 to the axis of bore 24 and receiving a lock spring `2S which is provided with ears 29 y(see HG. 3) adapted to tit in slot 21 in inner body iti- Means for preventing rotor 23 from rotating beyond its armed position in the fuze, wherein bore 24 is aligned with bore la, is provided by a ball 311 traveling in a helical groove 32 in the outer surface of cylindrical rotor 23 and in a straight slot 22 in the inner body li extending the width thereof.

Firing mechanism for the fuze is provided and consists of a lclosing disc 3d which closes bores 7, 3, and 9 in nose 3. A primary tiring pin 36 provided with a flange 35 and a point 37 is slidable in bore 8 and is held against rearward movement by a flange 35 which bears against a shoulder formed by bores 8 yand 9. Rearwardly in bore 17, there -is fixed a primer 38 carried by a holder 39. A primary ring pin 4i having a point 45 is slidable in bore iii and has a shear washer 42 integral therewith slid- -ab-le in a smaller bore ed coaxial between bores 16 and groove 3?, and is prevented from rearward movement by a shoulder formed by bores ld and ddl.

Operation of the arming mechanism-When the projectile, not shown, including the attached fuze of the invention, is Jdred from a gun, also not shown, the acceleration force acts to close ears 29 on lock pin spring 2S suciently to completely enter bore 27 thereby freeing rotor Z3 for rotation in `a clockwise direction 33. lIts rotation will begstopped when detonator bore 24 is in axial alignment with bore d6, whereby the fuze will be armed. This is accomplished by ball 31 traveling 4in helical groove 32 and down in straight slot 22 until it touches bore surface 5 of outer body 2.

Operation of the Jiri/'1g mechanism-The fuze is initiated by -impaet of the nose portion 3` with a target. Crushing of the nose portion 3 together with closing disc 34 will cause iiange 35 of the primary firing pin 36 to shear and advance point 37 to penetrate primer 3S in holder 39. The orifice 'dit delays the build up of gas pressure behind secondary tiring pin Alil. When sufficient pressure is built up, shear washer drZvwill be severed and the firing pin 41 will be propelled down bore i6 4in inner body `lit and point d5 will penetrate detonator 25 to iire booster charge 12 and the main charge of the projectile, not shown.

The time consumed in this process allows the shell to penetrate the target to some distance before the main charge, not shown, is detonated. This results in greater damage being done behind the target as would be desirable such as in ammunition used against aircraft.

The lconfiguration of the rotor 23 is such that it affects the static `and dynamic balance thereof. Bores 24, the half moon crirnps 26, helical groove l32 and bores 46,

di', d8, a9, 59, and 5i. all contribute to imparting the l static balance and minimize the effect of off center rotation and `also control the speed of rotation.

While the round is in a gun, rotor Z3 cannot rotate until after set back.

p lt is apparent from the foregoing, that an improved delay mechanism has been devised for use in a fuze that is highly simple of construction and effective in action.

While la preferred form of the invention hasbeen shown `and described, various modifications and substitutions of equivalents will occur to those skilled in the art after a. study of the foregoing disclosure. Hence, 'die disclosure sho-nld be Vtaken in an illustrative rather than a limiting sense. Y

ifhat is claimed is:

in a fuze, an outer body having 4.a nose portion, an inner body having an axial bore and a transverse bore normal to said axial bore, there being a first semi-circular,

straight, longitudinal groove in its inner peripheral surface thereof, a cylindrical rotor mounted in said transverse bore, a first detonator mounted in said rotor, said rotor having a secondsemicircu-lar,helical groove in its outer circumferential surface and disposed in opposed relation to said first semicircular groove, a detent ball seated for travelfbetween said first and second semi-circular grooves, said ball `adapted to limit the travel of said rotor between an unarmed to an armed position, means for preventing said rotor from rotating into said armed position, said means comprising a bore in, said rotor, there being a slot in lsaid inner body adjacent said transverse bore, a lock spring having outwardly curved ears, said spring normally housed in said bore in `said rotor and said ears normally received in said slot when said rotor is in its unarmed position, said lock spring to completely enter `said bore in said rotor upon acceleration force to unlock said rotor for rotation towards its armed position, a firing means for said fuze comprising, -a first axially aligned firing pin mounted References Cited inthe file of this patent UNITED STATES PATENTS 1,618,944 Pantoicek Feb. 22, 1927 2,397,781 Fischer Apr. 2, 1946 2,663,260 Thompson Dec. 22, 1953 2,712,284 Thomas et al. July 5, 1955 2,826,992 Czajkowski Mar. 18, 1958 2,834,292 Viasmensky May 13, 1958 3,013,496 Wenig Dec. 19, 1961V 

